Does anyone here have any good experience with sending part of the donation beforehand?

The consensus opinion on TER is to avoid deposits.

Too easy for a scammer to just keep the money and not show up.  I have never done deposits.

I've been burned twice.

Not worth the risk. IMO. If they’re requested I don’t bother. Some providers might not like reading this and I get why, especially the legitimate ones, do ask for this. But 90% of those asking for advances are scammers and you’re opening yourself up to a disaster. I just went through hell dealing with a SB so because of that, this is where I draw my personal line.

"because I dealt with a SB" and therein is the problem my dear, you were dealing with an amateur rather than a professional.

..... the companion is well-known and reputable.  I have sent many deposits to such companions, and have never had a problem.  Guys, we have to understand their realities, and their need to secure a commitment rather than reserve a time, and turn away other business, for someone who may just not show up.  It happens to them ALL THE TIME.

One of the gals who did me dirty was as solid as the rock of Gibraltar on TER, and looked up to as a model escort.  I knew her very well and seen her many times.   She unfortunately began to dabble in drugs, and that was all she wrote.   She even had the nerve to write me back about a year later and ask me how things are.   I told her.   That was that.

I’ve heard stories of well reputed providers doxing clients as well.

I would no more do that than I would ask a provider to let me pay her a week after the appointment.

Like who?

Well, if it had been during the "Hogan's Heroes" era, the provider would have paid you.

Savannah Marie - An established professional scamming mongers for deposits not once but multiple times.  Just recently this happened. read on...

If the provider is well known then yes, otherwise forget it. Sila Star requires a deposit but she has pages of reviews.  She's not going to screw up her reputation.